Given that scenario, I think that it does not come near to depicting the die off created by ten day's lack of potable water.

Ten days without functioning water extraction, purification, and delivery systems would cause an apocalyptic die off. Period.

Given that depicting such a die off would have ended the show less than half way through it's two hours, I think the movie was excellent. It showed a lot of likely scenarios for a variety of people caught in many, mostly utterly unprepared, situations. All did what they could to survive.

I think the show depicts far more people surviving than would be the case in an admittedly unlikely scenario. The apocalyptic prepper family depicted still had a perfectly reasonable situation to deal with which might well have eliminated them, but they were shown as both the best prepared and the most likely to survive. I think many others would not have made it, especially children and babies. The psychological downside of showing them as best prepared lies in their being hyper-prepared. Viewers could well come away with the belief that such a level of prepping is necessary to get through a major disaster, when no such thing is probably needed. Having water, canned goods and a means to cook is plenty for nearly all minor disasters: telling the audience that they need underground bunkers with outdoor surveillance systems, multiple giant propane tanks, and several years of food just discourages people from making preparations for short term problems which could save their lives. That's TV.

Overall, it was a fine attempt at showing a worst case scenario, which by it's nature as worst case is unlikely. Maybe it will even encourage a small number of people to buy flashlights and an extra flat of bottled water.